The present invention relates to an apparatus and a method for detecting biofilm in the water conduits of dental units.
One of the most important features of current dental units, and one which has undergone considerable development in recent years, especially in terms of technology and hygiene, is the water and air system. In the dental unit, the water line supplies fluids used by dental equipment and patients (water or physiological saline for tumblers and handpieces), or consumer units (swilling water for the spittoon), while the air line is used for certain items of equipment (air spray handpieces, cooling air and drive air).
As regards hygiene, different protocols have been devised to keep the conduits of the water line at the highest possible level of sterility at all times not only while a patient is being treated but also between patients.
To achieve this, the water line is treated with disinfection/sterilization cycles which bring the dental unit to an adequate level of sterility, although this level can be maintained only for a limited length of time. Indeed, a biofilm soon develops inside the water conduits. The biofilm consists of a colony of micro-organisms permanently attached to the inside surfaces of the conduits and encased in a loosely organized matrix of organic substances (for example, exopolymers, polysaccharides, etc.) excreted by the micro-organisms themselves.
The biofilm protects the bacteria from disinfecting/sterilizing actions and soon begins releasing bacteria into the user fluid. Once established, the biofilm also traps other micro-organisms and allows them to thrive within it.
The disinfectant/sterilizing products currently used (the most common is glutaraldehyde) will eliminate the bacteria in suspension but are unable to attack the biofilm in depth. As a result, it will not be long before the bacteria in the biofilm start multiplying again. Performing disinfection cycles with solvents capable of dissolving the biofilm (for example, strong acids or strong alkalis) is unfeasible because such solvents also corrode the conduits and equipment forming part of the dental unit, not to mention the fact that they are unsuitable on account of their biological incompatibility, which will not be described here.
To overcome this problem, the Applicant has devised and developed a sanitizing method and product designed to remove the biofilm, thus removing the protection and source of nourishment of the micro-organisms to expose them to the biocidal action of disinfectants, and using programmed disinfection/sterilizing cycles normally performed by customary dental units.
After sanitization, however, the dental unit must be checked and monitored not only to ensure that there is no biofilm still attached or suspended in the fluid, for example because the fluid has not been completely drained out of the water line after the sanitizing cycle or because the sanitizing cycle has not been sufficiently effective, but also to keep the hygienic state of the conduits under control to detect biofilm if it develops again so that another sanitizing cycle can be performed.
Whatever the case, depending on, or irrespective of, the above mentioned sanitizing method, the present invention has for an object to provide an apparatus for detecting biofilm, especially biofilm adhering to the inside surfaces of the water conduits of dental units, the apparatus being extremely accurate, quick to provide information on the hygienic state of the conduits, practical to use and easy to apply to the structure of the dental unit without substantially changing the architecture of the dental unit.
This object is achieved through an apparatus and method for detecting biofilm in the water conduits of dental units, especially biofilm adhering to the inside surfaces of the conduits; the apparatus being applicable to a water line equipped with a plurality of conduits for supplying fluids to handpieces and fluid consuming units that use fluid from a main supply or accessory fluids from corresponding independent lines; a portion of one of the conduits being equipped with means for detecting the presence of the biofilm on the surfaces of the portion itself.
In addition to the apparatus, the invention also provides a method for detecting biofilm comprising the steps of contacting the biofilm attached to surfaces with a reagent substance or fluid; altering the biofilm by the reagent substance or fluid; and detecting the alteration that has taken place in the biofilm using the aforementioned detecting means.